A modification package designed to increase the cubic inch displacement of a 6.4-liter Hemi engine to 426 cubic inches. It generally includes a crankshaft with a longer stroke, along with matching pistons and connecting rods to accommodate the increased stroke. These components work in concert to alter the engine’s geometry, resulting in a larger swept volume within the cylinders.
The purpose of this upgrade is typically to enhance engine performance, specifically to generate greater torque and horsepower. Increasing the displacement allows the engine to draw in and combust more air and fuel per cycle, leading to a more forceful power delivery. Historically, increasing engine displacement has been a common method to extract more performance from internal combustion engines, and this approach continues to be popular in the aftermarket performance industry.